Lamp



May 23, 1933. s, SPERTI 7 1,910,778

LAMP Filed April 30, 1931 Patented May 23, 1933 UNIT STATES PATENT OFFICE GEORGE BPERTI, 01'

T1011, 01' NEW YORK, N. Y A. CORPORATION 01 DELAWARE Application ma a ru so,

This invention relates to ultra-violet lamps and particularly to lamps of this character which embody an are such as a mercury arc.

\ "purposes. For example, ultra-violet lamps are extensively used for the irradiation of living subjects, both in clinics and in the home. The use of ultra-violet lamps for activating vitamins in food products is also well-known, and the action of ultra-violet rays in sterilizing liquids and foods, in stopping enzyme action, etc.,has been greatly developed. This wide use of ultra-violet radiation has resulted in the designing and building of various kinds of ultra-violet lam s, of which the most practicable at presexit is the mercury arc.

The object ofthe present invention is to provide a novel mercury arc lamp which is simple, cheap and durable in construction, economical and efiicient in o ration, and easy .to start and operate without s cial uipment'and without manual manipu ationo the lamp such as tipping, etc.

One embodiment of the lnvention isillus tuned in the accompanying drawing, but it is to be expressly understood that said drawing is for purposes of illustration only and is not to be construed as a. definition "of the limits of the. invention, reference being had to the appended claims for this purpose.

In the drawing,

Fig. 1 is a diagrammatic pers' tive view of a amp embodying the invention; and Fig. 2 isa sectional view of the lamp shown in Fig. 1.

In the form shown, the lamp is designed for operation on alternating current. The lamp casin or chamber 1, which may be of any suitabfi material translucent to ultraviolet radiation, comprises in the form shown a substantially U-shaped tube having pools of mercury 2 and 3 in the legs of the U which constitute mercury electrodes. Obviously the lamp chamber 1 may have any other suitable shape. The lamp chamber may be of quartz glass, which transmits substantially the com- 1831. Serial No. 584,082.

plete spectrum of the mercury arc, or-it may be of s ecial filtering glass or combined with a suita le filter so that the lamp doesnot emit waves shorter than a desired short wave length limit. uch filtering characteristics are desirable in many instances where certain waves cause harmful or'destructive effects.

I The electrodes 2 and 3 are connected to a suitable source of alternating. current by 'meahs of wires 4 and 5. In the form shown,

the lamp is operated from a transformer com- VINGTON, KENTUCKY, ABSIGNOB TO SI'EBTI LAX? COBPOBA- prising primary and secondary windings 6 and 7, the terminals of the secondary winding being connected to wires 4 and 5. The sec ondary winding may likewise be shunted by a condenser 8.

In the usual mercury arc lamp, the arc is started either by tipping the lamp or by applying heat to one of the mercury pools so as to vaporize a ortion of the mercury. The

present invention embodies an arc starting 7 means which is enclosed in the lamp chamber lintermediatethe electrodes 2 and 3 and which preferably comprises a member of ion adsorblng material such as zirconium oxide, thorium oxide, etc., which on being heated gives o'fi its adsorbed mercury ions and causes the are to strike between electrodes 2 and 3'. In theform shown, the are starting means comprises a tube 9, preferably of zirconium oxide, placed in the lamp chamber substantially midway between the electrodes 2 and 3. Within the tube 9 is a heating coil 10 the terminals of which may be connected to any suitable external source of current by means of wires 11 and 12.

When the lamp is to be used, current is supplied to the prima transformer winding 6 and the induced vo tage in the secondary winding 7, is applied to electrodes 2 and 3. At the same time the heating coil 10 is energized so that the tube 9 is heated. Mercury ions are thus driven 01! from the tube 9 and fill the lamp chamber 1 sufiiciently to cause the arc to jump between the electrodes 2 and 3.

This lampcomprises but a single integral unit, is of very simple design and construction and em ies no parts which can get out of order or require adjustment. The use of t ll the are starting means renders it unnecessary to provide special starting equipment such as mechanical arrangements for tilting or tipping the lamp or external heating means to vaporize the mercury from pools 2 and 3. The lamp is always ready for use and it is only necessary to turn a switch in order to start the operation.

It will be understood that the invention is not limited to the articular embodiment illustrated and described and that chan s may be made in the details of construction and arrangements of the parts without departing from the spirit of the invention. Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

-What is claimed is:

1. An alternatin current ultra-violet lamp comprisin in combination a casing translucent to u tra-violet light, spaced mercury pools in said casing, means for connecting said pools to a source of potential, and an are starting means in said casin intermediate said pools comprising a re ractory oxide member and means for heating said member to drive off mercury ions.

2. An alternatingjcurrent ultra-violet lamp comprising in com ination'a lamp chamber of material translucent to ultra-violet light of the desired wave lengths, spaced mercury electrodes in said chamber, means for connecting said electrodes to an external source or otential, a refractory oxide member in sai chamber intermediate said electrodes, and electric resistance means adjacent said member and connected to an external source of current for heating said member to drive ofi mercury ions therefrom.

An alternating current ultra-violet lamp comprising in combination a chamber translucent to ultra-violet light, spaced mercury electrodes in said casing, means for connecting said electrodes to an external source of potential, a tin of ion adsorbing material in said chamber intermediate said electrodes, a resistance coil in said tube for heating the same, and means for connecting said resistance coil to an external source of current.

l. An ultra-violet lamp comprising in comloination a. casing translucent to ultra-violet light of the desired wave lengths, spaced mercury electrodes in said casing, means for conmeeting said electrodes toan external source oi potential, and an arc startingmeaus in said casing intermediate said electrodes and comprising a tube of zirconium oxide, a resistance coil in said tube, and means for connecting said resistance coil to an external source of current.

5. An alternatin current ultra-violet lamp comprising in com ination a lamp chamber translucent to ultra-violet radiation of the desired wave lengths, said chamber being specification.

r GEORGE SPERTI.

substantially U-shaped, spaced mercury pools 1n the legs of the U and constituting mer- 

